An Impossible Descent

The Science Behind the Collapse of WTC7




On September 11th 2001, three buildings descended to the ground, each in a very short space of time. For each of these buildings, it has been demonstrated by careful measurements conducted on the copious video footage that, for a large part of the descent, accelerations indistinguishable from that of free-fall were achieved.

The fact that this is impossible for a structure undergoing a gravity collapse has been obvious to most scientists for years. Even Shayam Sunder, NIST spokesperson, has admitted as much, as you can see in this clip (ffwd to 0m20s).

Up until now, however, the proof of this has been inaccessible to the layperson, especially those who are easily intimidated by physics.  In this article I will explain why such a collapse is impossible in simple terms and illustrate the point with a couple of everyday examples. In this way I hope that the proof will become obvious to all.

I’m going to focus on WTC7 because it is easier to see the mechanics of what’s going on from the video clip. Also, as it wasn’t hit by a plane, this removes one unnecessary distraction from the discussion.


In order to understand the collapse, we just need to be familiar with one simple rule of physics: Newton’s Third Law. The best way to understand this is with a simple example, but, just to be thorough, let’s start with the scientific definition. Newton’s Third Law says that, when any body (let’s call it “A”) exerts a force on another body (“B”), then “B” exerts an equal and opposite force on “A”.

So let’s look at a simple example.

Imagine that you have a large receptacle full of trash and that you wish to compact the contents so you can get some more trash in. You put your foot on top of the trash and press down. Initially this is easy, but, bit by bit, it gets more difficult. Eventually you find you have to use your whole weight to compress it further and, eventually, even this is not enough and things come to a stop. You can’t compress it any more unless you grab on to something to get some leverage or get a friend to help.

A Trashy Analysis

Why is this? Well, here is where Newton’s Third Law comes in. Initially the trash, being loosely compressed, does not require much force to crush it. The force needed to compress it is exerted on it by your foot. At the same time, due to Newton’s Third Law, an equal and opposite force (the “Normal Contact Force”) acts upwards on your foot. This is because the top of the trash pile and the bottom of your foot are in contact and your foot (body “A”) is exerting a force on the trash (body “B”). Your muscles work to balance this upward force and it is by this exertion that you estimate how “hard” it is to compress the trash.

Notice that before your foot first touches the surface of the trash, pushing your foot down is very easy because you are just pushing air. When it hits the trash there is a little jolt because now there is the Normal Contact Force (NCF) acting up against your foot.

After a while, the rubbish becomes more compressed. This means that it now has more structural integrity, and it is this that makes it harder to compress it further. More force needs to be exerted and, by Newton’s Third Law, the NCF on your foot increases with it. Your muscle needs to exert more force to balance the NCF and so it seems “harder” to compress.

Now let’s try and use what we have learned and apply it to WTC7. In the course of this, I am going to make some assumptions just to make the thought experiment flow in as simple a way as possible. Some of the assumptions may seem unusual, so I am going to annotate them as we go and I will show at the end why they do not matter.

The Real Thing

Let’s start by looking at the clip of the building. Look at the clip and consider the first point of the main collapse (ffwd to 0m45s). We can see that the visible mass of the building moves down in one lump and we cannot see any destruction, at least not for a while. This means that the “zone of destruction” (ZOD) is somewhere near the bottom and does not move around much. Let’s assume (assumption1) that it is on the first floor and is fixed (assumption2).

Now we have to imagine the descent starting somehow, so let’s imagine that the first floor is removed (assumption3). I know this seems a little bit of an odd thing to do, so don’t forget to look at the notes at the end to see why we don’t need to worry about this.

The upper part of the building (let’s call it the “head” which, at this stage, consists of floors 2 through 47) will now start falling downwards under the force of gravity towards the stationary lower section (the “stump” which just consists of the ground floor). We can see this happening in the clip. It falls with free-fall acceleration because gravity is the only force acting. See fig1.



After a while the lower part of the second floor will be about to hit the upper part of the ground floor. At this point, let’s imagine two different scenarios.


In the first, let’s imagine that the second floor is removed from the picture (somehow). In this case the head will continue to fall downwards under gravity. Since gravity is still the only force acting, it will continue to accelerate at free-fall. In order for the ZOD to stay still, the second floor would have to be removed at the exact point in time that it reaches the position where the first floor used to be a few moments ago. So timing of the removal would be crucial. After this, the head would accelerate further and soon the third floor would be the next candidate for removal. Iterate this through all 47 floors and we will see a free-fall descent of the whole building.

Before we move on to the second scenario, let’s consider what would have happened if the timing of the removal of the second floor was mismanaged. If it were removed too early, then the ZOD would move upwards because the removal would be happening more quickly that the building was falling. If this were to continue, we would eventually see to ZOD in the clip – which we don’t. If, on the other hand, the second floor were to be removed too late, then the head would crash into the stump. We will cover what would happen in this case in the second scenario.


So let’s move to the second scenario then. In this case, we imagine what would happen if this “removal” (whatever that, in fact, means) does not take place. In this case, the bottom of the second floor (that is to say the bottom of the head) will strike the top of the ground floor (the top of the stump) just like your foot struck the top of the trash. See fig2.



Just as with your foot on the trash, the force will be exerted downwards on the stump (the trash) and the NCF (equal and opposite) will act upwards on the head (your foot). In the diagram, the force is in yellow and the NCF is in red. This NCF (on the head) is called the “retardation” because it acts to slow down the descent of the head. The NCF is in opposition to the force of gravity so we would observe a jolt as the forces on the head suddenly changed. In order to calculate the new value for the acceleration of the head, we need to resolve (i.e. subtract) these forces. Don’t worry if this seems complicated. The important thing is that now the head will be accelerating at less than free-fall thanks to the retardation.

I have a feeling that this retardation is the thing that most people fail to take into account when they look at this issue. But the retardation is a necessary consequence of Newton’s Third Law, and the application of Newton’s Third Law is a necessary consequence of the two bodies’ coming into contact. Most people think of the Law as applying only in static situations. However, there is no such caveat and to see it happening here in a dynamic situation is unremarkable.

Going back to the thought experiment, we can see that, now the two bodies are in contact, crumpling will occur just like it did with your foot on the trash. And this crumpling will continue. Just like with your foot, the force necessary to compact the remnants of the lower floors will increase. Eventually, it will increase so much that it will become equal to the weight of the head and we will no longer see acceleration of any kind but, instead, we will observe constant downward velocity of the head. The crumpling force (and thus the retardation) however, will increase still more and, eventually, we will see deceleration and an eventual halt.

This, I think you will agree, is very different from a free-fall descent.


Let’s consider another perhaps easier example. Imagine two identical automobiles: a stationary one (A) and another (B) moving at a constant velocity of 10m/s. See fig3.



Now imagine that B hits A. See fig4.



After the collision, the crumpled unit that consists of both cars will be moving at 5m/s. In physics terms, this is called “Conservation of Momentum”, but like most practical physics, we can also just view it as common sense. I hope that most people will be able to see this intuitively without a lengthy discussion of momentum.

Let’s imagine that the collision process takes 1s to complete (from the first instant of the impact up to the point at which both vehicles are moving along as one unit).  This means that A will have accelerated at 5m/s/s and that B will have decelerated by 5m/s/s. During the 1s, the mechanics of the crumpling will have absorbed the change in momentum required to make the new composite object travelling at 5m/s. The important thing is the deceleration of B.

Now this example isn’t very similar to WTC7, so let’s see what can change to make it a better fit. Well, the head was very big as compared to the stump, so let’s make B a big truck. Also, the stump is not on wheels, so let’s remove the wheels from A and embed it in concrete to anchor it down. The stump cannot go anywhere because there is solid ground underneath it, so let’s build a big concrete wall behind A and assume that it is infinitely strong. Lastly, the head was accelerating (before impact) under gravity, so let’s imagine a robot driver with its foot on the gas. See fig5.



Now we can see that B would be accelerating until the moment of impact but, after impact, we would see a sharp reduction in acceleration. As crumpling proceeded, the acceleration would decrease more until it became deceleration and eventually the whole thing would come to rest. At the end A and B would still be visible, and would be roughly in the position that A once occupied.

This is not what we observed in the clip of WTC7 at all.

Now imagine what we would see if layers of B were to be removed from the front (of B) before the impact could happen. In this case, the acceleration would continue (because the robot foot is on the gas and there is nothing to slow the truck down) until there was nothing left of B.

This is exactly what we observe in WTC7.

So what can we conclude? Well, Newton’s Third Law has taught us what has to have happened in order to produce the observations we can see in the clip. Each floor of the building would have had to have been “removed” in a very precisely timed and orderly manner so that no real contact ever took place between the head and the stump. If, at any point, there was contact, then a NCF would have been produced and that would have resulted in retardation.

No such retardation was observed.

Now watch the physics expert, Dave Chandler from @AE911Truth, explaining the same thing (ffwd to 1m20s).

Now we have worked out what must have happened, we need to propose a mechanism (or model) that could produce this. Specifically, we need to suggest how this “progressive removal” could have happened.

My proposed model is that of controlled demolition, and it is my claim that this model would produce both the “removal” and the “timing” that are required to produce the observations we see. Of course, it may be possible to come up with an alternative model. I am not aware that anyone has done so, but, if anyone has, I would be very interested in analysing it to see if it could more accurately predict the observations we made. This, of course, is the scientific method. All we can say is that controlled demolition is the most likely explanation we have considered so far. We should always keep an open mind in case something new comes along.

All that remains now is to tidy up those loose assumptions:

Assumption1 (ZOD is at the first floor). It makes no difference if we assume the ZOD starts at any other floor. The stump just starts out being bigger and the head smaller (or vice versa).

Assumption2 (ZOD is fixed). It is perfectly OK for the ZOD to move around (though not too far, otherwise we would see it in the clip). It just means that the timing for the “removal” would be more difficult to work out, making the chance of a collision more likely. Remember, if there is a collision, then we will not get the results that we have observed.

Assumption3 (First floor is removed at the start). If this seems weird, imagine just a small section 1m in height being removed. The argument above still stands, the only difference being that the first step happens more quickly. If that’s still weird, imagine this removal being applied to a section that is infinitely small in height. The argument above now happens at the start and there is no jolt. The rest is the same.


The World Trade Center

Evidence for Controlled Demolition


On 11th September 2001, three buildings were destroyed in New York City. The destruction was complete and saw all three buildings fall within the space of a few seconds. Two models have been proposed to suggest the cause for this destruction. The first, the official narrative, is that gravity alone caused it. The second is that it was caused by controlled demolition

In the last few years, a wealth of new evidence has come to light that points towards controlled demolition, and, as such, we now have a large portfolio of corroborating information. While this can leave us in no doubt as to our conclusion, the large and complex body of evidence can be hard to digest for newcomers to this field of research. In this article I hope to make this evidence more accessible to the reader by presenting the facts as a “Quick Start Guide”.

The evidence we have falls into a number of categories.

Controlled Demolition

Let’s drill down on each one in turn and look at the detail.

Physical Evidence

This kind of evidenced involves observing the events as they happened. With most crimes, this is impossible. However, the events of 9/11 were some of the best photographed and videoed in history. This means we are able to look at the dynamics of the destruction and focus in particular on Newton’s Laws of Motion.


In a court of law here in the UK (and in many other countries), we need “proof beyond all reasonable doubt” to assure a conviction. If we can show that, for a particular story to be true, the laws of physics would have had to have been violated, then we have proof beyond all possible doubt that this story is false. This is a much greater degree of certainty than that which would be required in any court. For instance, in a murder case, if we can prove that the murderer would have had to have travelled at a speed greater than that of light, then we know that the story is false not just beyond all reasonable doubt, but also beyond all possible doubt.

To disprove the gravity-collapse model by this means, we would need to do two things. First, we would need to show that no gravity collapse could ever happen at freefall (whilst still following the laws of physics). Second, we would need to show that freefall did indeed happen in this case. Note that we do not need to show that freefall happened throughout the whole descent, just for a part of it. Nobody is claiming that the acceleration was constant.

Architects and Engineers for 9/11 Truth (ae911truth) have done most of the ground-breaking research on this subject. In this clip David Chandler, top physicist for ae911Truth, explains both why a gravity-collapse cannot result in freefall, and that WTC7 (plus the other two towers) did indeed come down at freefall for a substantial part of its descent.

This evidence alone is sufficient to prove the action of controlled demolition and disprove any notion of a gravity-collapse.

Lateral Projection

The thing about gravity is that it acts straight downwards on an object, never sideways or in any other direction. There may be a slight amount of scatter as objects fall and hit each other, but, if we see objects move horizontally with great speed, we must assume that a force other than gravity is acting. In the gravity-collapse model, there is no other force acting, so, if we observe this kind of behaviour, we can conclude that this model is false. Once again, David Chandler shows us in this clip his analysis that shows speeds of around 70mph for the lateral projection of components of the buildings.


Forensic evidence is similar to physical evidence, except that crime scene is examined after the event to give us clues as to what went on. In the case of 9/11, this is very difficult because the crime scene was disturbed and most of the evidence removed before it could be examined.

Thermite Residue

After the attacks, a number of people gathered samples from the thick dust that settled all over Lower Manhattan. Some of these samples have been analysed and have been found to contain thermite residue. Thermite is a chemical mixture that burns at a very high temperature. If handled correctly, it can be used to cut steel columns as you can see here (ffwd to 8m00s). After combustion, it leaves behind a tell-tale residue.

Probably the best study of thermite residues from 9/11 is that of Dr. Steven Jones. You can see his film here. Dr. Jones’s study is a scientific one and has been subject to peer-review. Yet, for following the rules of science and eschewing the non-science of the official story, he was forced out of his job at the university at which he lectured.

Video & Photo

As we know, this was one of the most photographed events in history, so evidence of this form is plentiful.

Molten Steel

Steel melts at 1540 degrees Celsius. Aviation fuel burns at around 250 degrees Celsius and an office fire somewhat lower than that. So that means that neither the fuel fire nor the resulting office fire could have caused the steel to melt.

However, there is plenty of evidence of molten steel on the day as you can see here, so this must have been due to some other source of energy – the thermite that was used to cut the columns.


When the charges go off during controlled demolition, air pressure increases in the vicinity of the charge and this often causes windows to blow out and a puff of smoke to appear. These phenomena are called “squibs”. If we can see them, as you can here, then it is an indication of explosives.

Pyroclastic Clouds

A pyroclastic cloud is a mixture of very hot gas and small particles. The cloud usually emanates from a heat source and flows away from it at substantial speed as it is pushed by gas expanding at the source. These clouds are normally associated with erupting volcanoes or large explosions. They are not formed as the result of falling debris (that just forms a normal cloud). There is no shortage of evidence for these clouds.

Recorded Explosions

Explosions are normally pretty loud and so easy to hear and record. If there were indeed explosions, then it is likely that these would have been recorded. Indeed, there are plenty of such recordings. See here and, once again from David Chandler, here.


Before we launch into this, let’s think for a moment about what we mean by miracle. A miracle is an event that is exceedingly unlikely to occur, yet does. Let’s look at an example:

On my desk is a glass of water. The laws of quantum dynamics say that there is a very tiny possibility that all the water could jump out of the glass and land on my keyboard – all on its own. The only snag is the word “tiny”. If we actually look at the statistics, we see that although it is possible in theory, on average the amount of time we would have to wait for this to happen exceeds the current age of the universe (by a big margin). Needless to say, nobody has ever observed this happening. Now, let’s say that the water does indeed fly out. What could be the explanation? We already have the scientific possibility above, but it is so unlikely that we can rule it out. Another possibility is that there was an intervention by some deity. Being an atheist, I wouldn’t accept this and most religious people I know, being deists rather than theists, wouldn’t accept it either. So I think we can rule this one out too. However, there is one further explanation: intervention by a human. In this case the most likely explanation is that I spilt the water myself and then kept quiet.

If an observed event is sufficiently unlikely to have happened on its own, then human intervention should be our first suspect.

Simultaneous Snapping

Have a look at the descent of WTC7 here (ffwd to 1m40s). The first thing you will notice it that it falls straight downwards – at right angles to the ground. There is no tipping to one side or the other and the movement is continuous and smooth. The other thing is that the zone of destruction is in one place only – near the base of the building. As the building descends, a floor is destroyed at the zone of destruction, followed shortly by the next floor and the next, etc.

The building, as you can see here, had 58 perimeter columns and 25 core columns. In order for the building to fall one storey, the anchor points between a floor and all the columns would have to be broken simultaneously (within 0.1s of each other). If some anchor points had snapped while others did not, then the floor would have tipped to one side with the intact anchors at the top of the resulting sloped floor. Any slight imbalance like this would tend to be amplified on collapse of the next floor as there would be more stress and weakness at the side of the building with the snapped anchor points (the lower part of the slope) and more rigidity at the side where the anchor points held out (the higher).

A fire is essentially a random and chaotic chemical process. For a fire to snap these 83 anchor points simultaneously would have been incredibly unlikely. Nature just doesn’t spontaneously create order from disorder like that.

After the collapse of the first floor, the next floor would then have to suffer the same unlikely demise. So now we have two exceedingly unlikely events separated by a fraction of a second. Not only that, the timing of the two events relative to each other would need to be precise if the whole descent is to happen at near freefall within a few seconds.

As each unlikely event follows the last, the laws of statistics demand that we multiply together the probabilities of each as we go. Multiply this up like this for the whole 47 stories and you start to realise that this is so enormously unlikely that it does indeed constitute a miracle.

As an aside, it is interesting to note that, even if this incredibly unlikely sequence of events had occurred, we would still see the central columns standing after the descent. In fact we saw no such thing.

So what would we expect to see in a gravity-collapse then? Once again, David Chandler explains this here.

Three Buildings, One Day

NIST tell us that fires raging in the buildings caused them to be weakened and that resulted in their gravitational collapse. Before 9/11, no steel framed building had ever collapsed under gravity as a result of fire. On 9/11 (NIST tell us) three buildings did just this. Since 9/11, no further buildings have collapsed like this, even though a number of them have caught fire. This divergence from the norm would be very unlikely and, as such, would constitute a miracle.

Lateral Projection

Some people have postulated that the lateral projection of debris we talked about earlier could be caused by steel beams’ being put under tension and then being allowed to spring apart. If such an event were to happen, it would be very unlikely. Looking at the videos we can see these projections happen over and over again. This unlikely “springing apart” to be happening many times like this would constitute a miracle.


Eyewitness testimony is very important when it is the only kind of evidence available. When there is plenty of evidence, it can still be useful for corroboration.

Witness to Explosions

There are an enormous number of witnesses who reported explosions throughout the day as you can see here.


For someone to be convicted of a crime, it has to be demonstrated that they had the opportunity to so do. There is some evidence of opportunity for the planting of the explosives for the demolition, but perhaps the complete story will only be uncovered if there is ever a proper investigation.


During the weeks and months leading up to 9/11, there were numerous reports of power-downs, strange evacuations and drills. You can hear about them here.


One can tell a lot about what happened by observing people’s behaviour. Their behaviour at the time can be analysed along with their behaviour subsequently.


Foreknowledge is important because, if we can show that someone had knowledge of an event prior to its happening, then that means that either they planned the event or they have come into contact with the people who did. Any investigation should start by talking to people showing foreknowledge.

Evidence for foreknowledge is plentiful. The most famous example of this is the BBC’s Jane Standley announcing the destruction of WTC7 some twenty minutes before it happened. This was not something unique to the BBC, as the same thing happened with other news outlets.

Next we have the “Dancing Israelis”. These individuals were seen filming the event as it happened while laughing and cheering. You can hear about their story here.

Lastly, we have the fact that some of the first responders seemed to know that WTC7 was going to be destroyed before it happened as you can hear from this testimony and see for yourself in this clip.


Larry Silverstein, the owner of the lease on the World Trade Centre site, has admitted that he gave the order to have WTC7 demolished. You can see his interview here (ffwd to 1m45s).

Market Trading

Irregularities in market trading can indicate insider dealing, which, in turn, is evidence of foreknowledge. In the days leading up to 9/11 there were large increases in the volume of Put Options (ffwd to 0m30s) on the stock of the two airlines involved. For those of you unfamiliar with financial markets, a Put Option is effectively a bet that the stock price of a company will go down in the near future. Put Options (and the opposite, Call Options) are placed in the market all the time and are not in themselves proof of anything. What signals the insider dealing is when there is a massive increase in traded volumes coupled with a large shift towards, in this case, the Put Options (as opposed to the Calls).

Common Sense

Scientists can build a case by analysing data, but what do you do if you’re not a scientist? The short answer is that you can do the same thing. Most physical science is just a formalisation of what most people term “common sense”.

2 planes, 3 buildings

The official narrative says that two planes were involved, each plane hitting one of two towers. The third tower was not hit by a plane. Still, however, the third building, WTC7, came down with acceleration close to that of freefall. Even if there were two buildings and two planes, we have seen that to assume that the planes were the cause is to commit the logical fallacy of Post Hoc Ergo Propter Hoc. The destruction of the third tower augments this logical fallacy to the level of a farce.

Orthogonal Descent

We have already talked about the fact that the three towers descended at right angles to the ground. But how often do we see such a thing in nature?

How about a tree being felled? At the moment of descent, the upper part of the tree rotates around the cut that has been made with the axe and falls to the side. You would not expect to see the upper part pass vertically through the lower part, reducing itself to sawdust as it went. If we saw this, it would be very strange.

Another great example is a Jenga tower. When it falls, the upper part rotates around a point some way up the tower. Because the blocks are not held together, the motion soon degenerates into chaos. If, instead, we saw an ordered event in which the tower collapsed onto its own footprint and everything was converted to sawdust, we would think that something very odd had happened.

How often do we see orthogonal collapse in nature? The answer is: never.

To Conclude

We have seen that the body of evidence for controlled demolition forms a consistent and convincing portfolio and that the conclusions are unavoidable for anyone who takes the time to research. But why is it that, nevertheless, a lot of people have a hard time accepting it?

The Free Press (here for example) cover the issues we have talked about here and also the broader issues surrounding 9/11 as a whole. Why is it that the Mainstream Media never touch it?

These are questions which I will address in my next few articles.